As an oil-in-water emulsified product used as cream, particularly whipping cream used mainly in the confectionery and bread-making fields, natural fresh cream, which is manufactured by separating milk fat from raw milk, has hitherto been used. However, although fresh cream is excellent in such a degree that there is no analog in respect of flavor, in an emulsion state before whipping, sudden rise of the viscosity or solidification so-called bate is liable to occur due to rise of the temperature thereof during preservation or vibration during transportation, and there has been difficulty in the aspect of its handling. Furthermore, fresh cream has had such problems that the quality of raw milk as its raw material is liable to change depending on seasons, and it is expensive.
Therefore, as oil-in-water emulsified products which are comparatively inexpensive, easy to obtain and comparatively stable in quality, there have been developed compound-type oil-in-water emulsified products wherein part of the milk fat is replaced with vegetable fats-and-oils, and vegetable-type oil-in-water emulsified products wherein all of the milk fat is replaced with vegetable fats-and-oils.
As vegetable fats-and-oils used in vegetable-type oil-in-water emulsified products, there can be mentioned lauric fats-and-oils containing much lauric acid as a saturated fatty acid having 12 carbon atoms such as coconut oil and palm kernel oil; vegetable fats-and-oils containing much fatty acids having 16 or more carbon atoms such as and palm oil and rapeseed oil, and hardened oils and fractionated oils of these vegetable fats-and-oils; and mixed oils of these fats-and-oils; etc.
Oil-in-water emulsified products obtained using only lauric fats-and-oils exhibit very good melting mouthfeel, but they have a problem that their viscosity tends to rise due to temperature change, and it is difficult to maintain a moderate foaming state and hardness suitable for work. As to oil-in-water emulsified products obtained using only lauric fats-and-oils, their preparation becomes possible when their fat content is made to be low, but problems have yet remained that when they are used as cream, particularly whipping cream, they are brittle, and poor in shape-retaining properties, and so on as the physical properties of whipped cream after whipping.
On the other hand, since oil-in-water emulsified products obtained by using together lauric fats-and-oils and hardened oils of vegetable fats-and-oils containing much fatty acids having 16 or more carbon atoms such as palm oil or rapeseed oil have good balance of melting mouthfeel, emulsification stability and shape-retaining properties, they have hitherto widely been used as cream, particularly whipping cream (e.g., see Patent Documents 1 and 2).
However, in recent years, a theory has appeared that trans fatty acids contained in hardened oils are nutritionally undesirable, fat-and-oil-containing foods of a reduced trans fatty acid content have socially come to be claimed, and, for example, in U.S.A., it is obligatory to make an indication on foods containing trans fatty acids in an amount exceeding a certain standard. Therefore, also as to oil-in-water emulsified products used as cream, particularly whipping cream, it has come to be claimed not to use hardened oils of vegetable fats-and-oils containing trans fatty acids.
As an oil-in-water emulsified product substantially containing no trans fatty acid, one wherein a lauric fat-and-oil and a middle-melting fractionated oil of palm oil are used together, or the like is conceived (e.g., see Patent Document 3).
However, although an oil-in-water emulsified product obtained by using together a lauric fat-and-oil and a middle-melting fractionated oil of palm oil contains substantially no trans fatty acid, when the oil-in-water emulsified product is one having a high fat-and-oil content (i.e., one containing much fat-and-oil), it has a problem, particularly in emulsification stability, and could not be satisfactory in practical use. Thus, although an oil-in-water emulsified product of a high fat-and-oil content, i.e., containing much fat-and-oil, used as cream, particularly whipping cream, is very advantageous in the aspect of good taste, it has yet been unsatisfactory in respect of quality.
Therefore, development of an oil-in-water emulsified product containing substantially no trans fatty acid, having a high fat-and-oil content but nevertheless having high emulsification stability, and being good in whipping characteristics such as melting mouthfeel, foaming properties and shape-retaining properties has been desired.    Patent Document 1: JP 10-075729 A    Patent Document 2: JP 2002-034450 A    Patent Document 3: JP 05-219887 A